As someone on the far-left. The Left tends to attract a lot of mentally ill social outcasts who don't fit into regular society for obvious reasons, instead of learning to adapt, they want everyone to adapt to them, this leads to Leftist orgs getting overrun with mentally ill hyper-individualist idpol types who basically treat Leftist orgs and ideology as their own personal circlejerk self-help group, and thus have a massive, MASSIVE issue with any sort of standards and gatekeeping.
This is how Trans ideology, went from something actually, at least coherent and somewhat in line with other gender theory (Though arguable with many Pre-Zoomer feminists) with Trans-Medicalism, to basically slippery sloping to attack Helicopter, Tucute fluidity bullshit, because they also know, if they gatekeep, they can be questioned themselves based on their self-identification or if they're actually part of the left for actual leftist reasons or just narcissistic self-aggrandizement.
Despite absolute clear cut evidence of AGP and blatantly bullshit, evil, manipulative predator men like Chris and Jonathan, who clearly aren't Trans but a mix of delusional, AGP and predatory men doing it to clearly enter vulnerable women's spaces because of self-interest, they have to adhere to the zealot Tucute orthodox that Noooo Jonathan and Chris are obviously still heckin valid, because if they don't, that opens up gatekeeping and again, they fear the crosshairs will come on them and Transmedicalism will win out.
On top of this, you have the media like the Guardian and other such outlets, purposely push this Tucute Zealot fludity my hecking identity bullshit, because they know it's clearly bullshit to anyone with eyes and it generates outrage and clicks, the Guardian knows men will pretend to be women to be predators and take advantage, they also know, pretending to be retarded, will get them outrage clicks. You also have all the LGBT activist grifters who basically push this shit for their job because they've basically won all the common sense LGBT battles, and should be out of work.
My experience though is more and more in private conversations, that most non-Zoomer leftists despise this fucking shit and clearly think that Tucute Trans shit has basically become a hyper narcissistic cult and it seems to be coming out more and more as an open opinion within the left itself, even with podcasts like Chapo shitting on Idpol cultist crap and the rise of StupIDpol and Class First caucus (now the largest caucus membership and specifically anti-Idpol) within the DSA. I think the Tucute cult will come down crashing and burning in the next few years, when they've lost their leftist allies, which seems to be the way the wind is blowing from my experience, they're basically just going to be seen as rambling cultist fetishist retards.
TL;DR: Left is filled with retards who are scared of gatekeeping because they're not part of the left because they're leftists, but for a narcissistic outcast circlejerk club